Internal small bore roll syphon

ABSTRACT

A SYPHON SYSTEM FOR USE WITH ROTARY HEAT EXCHANGING ROLLS HAVING A RELATIVELY SMALL AXIAL BORE IN WHICH THE HEAT EXCHANGING MEDIUM IS INTRODUCED AND REMOVED IN ORDER TO HEAT OR COOL THE ROLL. THE MEDIUM REMOVING APPARATUS IS PRIMARILY MOUNTED INTERIORLY OF THE ROLL HAVING CONDUITS EXTENDING FROM ONE END OF THE BORE. THE HEAT EXCHANGING MEDIUM IS REMOVED CIRCUMFERENTIALLY ABOUT THE INNER SURFACE OF THE BORE, AND THE SYPHON SYSTEM INCLUDES CONDIUTS FOR BOTH INTRODUCING AND REMOVING THE HEAT EXCHANGING MEDIUM FROM THE ROLL BORE.

1971 v D- L. CALKINS INTERNAL SMALL BORE ROLL SYPHON Filed April 9, 1969 S m a 5 mm O m m IM A L D L A N O D I m w A 24 n M 2 United States Pate 3,614,983 INTERNAL SMALL BORE ROLL SYPHON Donald L. Calkins, Three Rivers, Mich, assignor to The Johnson Corporation, Three Rivers, Mich. Filed Apr. 9, 1969, Ser. No. 814,677 Int. Cl. F2843 11/02 US. Cl. 16589 8 Claims ABSTRACT OF THE DISCLOSURE A- syphon system for use with rotary heat exchanging rolls having a relatively small axial bore in which the heat exchanging medium is introduced and removed in order to heat or cool the roll The medium removing apparatus is primarily mounted interiorly of the roll having conduits extending from one end of the bore. The heat exchanging medium is removed circumferentially about the inner surface of the bore, and the syphon system includes conduits for both introducing and removing the heat exchanging medium from the roll bore.

BACKGROUND OF THE INVENTION The invention pertains to the field of art of removing a heat exchanging medium, such as water, steam condensate, or other such medium from a rotating heat exchanger roll such as a dryer roll used in the manufacture of paper products.

The use of rotary heat exchanging rolls in the production of web and strip products, such as paper and fabric, is well known. Such rolls are of a cylindrical configuration and the web of material which is to be heated or cooled is passed over the rotating roll outer cylindrical periphery at the desired speed that a transfer of heat may take place between the roll and the web. In the usual construction of such heat exchanging rolls the cylindrical wall is relatively thin such that a rapid transfer of heat between the interior of the roll, and the exterior surface takes place.

However, with certain types of heat exchanging rolls wherein it is particularly desirable to maintain uniform and close temperature control, a thick wall roll or drum is used wherein the large mass of the roll produces close temperature control. Such rolls have a relatively small axial bore into which the heat exchanging medium is introduced, and such rolls are known as small bore rolls.

With small bore rolls it is particularly important that the heat exchanging medium be rapidly circulated within the bore and removed therefrom in that only a relatively small amount of heat exchanging medium is within the bore at any one time, and the temperature of the medium will often rather quickly change. In that it is common practice to run web producing equipment at relatively high speeds another problem which affects the heat exchanging capabilities of the equipment arises from the rimming of the heat exchanging medium, such as steam condensate, throughout the entire periphery of the roll bore. Due to the high rate of rotation of the roll the condensate will form a film about the inner surface of the bore which partially insulates the mass of the roll from the medium, steam, for instance, within the bore. Thus, if this film of condensate can be quickly removed, and maintained at a minimum thickness, the efficiencies of the system are improved. The problems resulting from this phenomenon are discussed in the assignees United States Pat. 3,242,583.

Prior art devices concerning the reoval of heat exchanging medium from small bore rolls have not been well developed. Reference is made to the US. Pats. 1,990,- 166 and 2,460,059. Prior art syphon devices of a conventional nature are usually not readily adaptable to small bore rolls in view of space and clearance limitations, and thus with small bore rolls the development of effective medium removal equipment has been largely ignored. The applicant has been concerned with the problem of removal from small bore rolls, and one approach to the problem is disclosed in his copending US. application Ser. No. 726,357, filed May 3, 1968, now Pat. No. 3,498,591.

SUMMARY OF THE INVENTION It is a basic purpose of the invention to provide a heat exchanging system for use with small bore rotary heat exchanging rolls wherein the removal system is primarily mounted within the interior of the roll bore, minimizing the amount of equipment located exteriorly of the roll, and wherein the waste heat exchanging medium can be efficiently removed from the roll bore to permit maximum heat exchanging efficiency.

In the invention a condensate removing member is mounted within the roll bore and is sealed with respect thereto. In the disclosed embodiment the removal member also includes conduit and passage means for introducing the heat exchanging medium into the bore.

The member includes a medium removing opening disposed adjacent the periphery of the member, which places the opening adjacent the bore inner surface. Thus, the medium is removed adjacent the bore inner surface. Additionally, an annular orifice is defined about the member communicating with the opening such that the condensate may be removed through the entire 360 periphery of the bore, which minimizes the thickness of the medium film located on the bore surface.

In the preferred embodiment a pair of conduits communicate with the medium removing member, one conduit being located within the other. The interior conduit is connected to the medium removing opening, and the exterior conduit communicates with an inlet passage for introducing the heat exchanging medium into the roll. Preferably, an elongated conduit is attached to this inlet for introducing the heat exchanging medium into the roll at a location remote from the removing opening. Conventional rotary joint means communicate with the ends of the conduits extending from the roll bore for establishing communication between the conduits with supply and exhaust systems of a conventional nature.

In order to minimize the sealing apparatus required, an annular seal is mounted upon the medium removing member wherein the member is sealed to the roll bore. The apparatus requires only one additional mounting flange for fixing to the end of the roll, and it is possible to assemble the apparatus to the roll, and remove the equipment therefrom, in an expeditious manner to facilitate maintenance.

BRIEF DESCRIPTION OF THE DRAWINGS The objects and purposes of the invention will be appreciated from the following description and accompanying drawings wherein:

FIG. 1 is a diametrical, sectional view of a small bore heat exchanging roll and syphon system apparatus in accord with the invention,

FIG. 2 is an enlarged, diametrical, cross sectional view of the medium removing and introduction apparatus,

FIG. 3 is a sectional, elevational view taken along section IIIIII of FIG. 1,

FIG. 4 is a detail, elevational view of the bore receiving member, and

FIG. 5 is an elevational, sectional view taken through the inlet conduit along section VV of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT The relationship of the basic components of the invention will be appreciated from FIG. 1. In this figure, a small bore heat exchanging roll is illustrated at which includes an outer cylindrical surface 12 for engagement with the web to be treated, and bearing surfaces 14 are located at the ends of the roll for engagement with bearings 16, schematically illustrated.

The roll 10 includes a concentric bore 18 having an inner surface 20 and the bore will usually intersect both ends of the roll. In the described embodiment one end of the roll bore is sealed by an internal sealing member 22.

The syphon apparatus of the invention includes a heat exchanging medium member 24 received within the roll bore, and this member also includes means for introducing the heat exchanging medium, such as steam, into the bore. The member 24 is of a cylindrical configuration having an enlarged diametrical portion at 26, and a reduced diametrical portion 28. A circular plate 30 seals the innermost end of the member 24, and the inlet conduit 32 is attached to and passes through an inlet passage in the plate for communication with the interior of the member 24.

Annular sealing rings 34 are located within a groove 36 defined on the large diameter portion of the member 24, and it will be appreciated that the maximum diameter of the portion 26 is only slightly less than the diameter of the roll bore 18 wherein a relatively close relationship between the member 24 and the bore is achieved which is maintained fluid tight by the sealing rings 34.

Interiorly, the member 24 includes a chamber 38, which communicates with the end of the inlet conduit passage 32, and a chamber 40, which communicates with an opening 42 disposed adjacent the intersection of the peripheral portions 26 and 28, and intersects the portion 28. The opening 42 constitutes the heat exchanging medium removal opening.

The heat exchanging medium is removed from the member 24 through a conduit 44 aflixed to the member communicating with the chamber 40 and extending from the left end of the roll as viewed in FIG. 1. The heat exchanging medium is introduced into the roll through conduits 46 and 46' concentrically encompassing the conduit 44, and communicating with the chamber 38 and the inlet conduit 32.

The conduits 46 and 46' associate with a mounting flange 48 aflixed to the end of roll 10 by screws or other fasteners, not shown. The conduit 46 may terminate within the flange as shown, or be formed of a single piece to extend therethrough. If the conduit 46 terminates in the flange, an extension 46' of the conduit is affixed to the flange whereby the concentric relationship between the conduits 44 and 46 is maintained to the rotary joint 50 to which is connected the syphon conduit 52, and the supply conduit 54. The rotary joint 50 may be of any conventional construction, such as that shown in US. Pat. 2,385,421.

Inlet conduit 32 preferably extends substantially the length of the roll 10 having an outlet 56 disposed adjacent the seal 22. Thus, the steam, or other heat exchange 4 medium, is introduced into the roll bore at a location remote from the medium removing opening 42. Of course, if desired, nozzle openings may be provided along the length of the inlet conduit 32.

The conduit 32 is supported at spaced axial portions by support plates 58, FIG. 5, which are of a noncircular configuration wherein clearance is provided such that the heat exchanging medium may flow axially through the bore.

In operation, the heat exchanging medium which may be steam, or hot water, if the roll is to be heated, or may be cold water, if the roll is to be a cooling roll, is introduced into the joint 50 through the supply conduit 54, and passes into the roll bore 18 through conduits 46 and 46, chamber 38 and conduit 32. As the medium flows from the right end of the roll bore, FIG. 1, toward the left end of the bore, heat transfer occurs between the medium and the roll. Usually, the speed of the roll will caues the liquid within the bore to be thrown against the inner surface of the bore to produce rimming. The meduim is removed from the bore through the opening 42, and as the reduced diameter portion 28 of the member 24 produces an annular orifice communicating with the entire peripheral surface of the bore 18 the condensate may be uniformly removed from the bore and thereby reduced to a minimum radial thickness. The medium is removed from the bore through the chamber 40, conduit 44 and the syphon conduit 52 communicating with the joint.

In that the member 24 seals the bore with respect to the associated roll end it is not required that sealing means be employed with the flange 48, and it will be appreciated that the construction of the apparatus of the invention produces a very clean installation in that the majority of the apparatus is located within the roll bore, or directly upon the end of the roll.

It is appreciated that various modifications to the inventive concept may be apparent to those skilled in the art and it is intended that the invention be defined only by the scope of the following claims:

I claim:

1. A syphon system particularly suitable with small bore heat exchanging rotary rolls comprising, in combination, a heat exchanger roll having ends, a peripheral heat exchanging surface and an axial cylindrical bore having an inner surface and intersecting one of said roll ends, bearing means rotatably supporting said roll, means for introducing a heat exchanging medium into said bore, a cylindrical medium removing member Within said bore having a maximum diameter slightly less than the diameter of said bore, a medium receiving opening defined in said member directly adjacent said bore inner surface and communicating with said bore, sealing means carried by said medium removing member sealing said member with respect to said roll bore, said sealing means being located in the axial direction of said roll intermediate said member opening and said roll intersected end and, a medium removing conduit communicating with said member and said opening for removing the heat exchanging medium entering said opening from said roll.

2. In a syphon system as in claim 1 wherein an annular heat exchanging medium receiving orifice is defined by said member adjacent said bore inner surface, said opening communicating with said orifice wherein medium may be drawn from said roll bore throughout the circumference thereof.

3. In a syphon system as in claim 1 wherein said means for introducing a heat exchanging medium into said bore includes a first conduit affixed to said member extending from said intersected roll end, and an inlet passage defined in said member communicating with said first conduit and said bore.

4. In a syphon system as in claim 3, a distribution conduit within said roll bore communicating with said member inlet passage, and at least one outlet defined in said distribution conduit remotely spaced from said member.

5. In a syphon system as in claim 3, wherein said medium removing conduit is Within said first conduit aflixed to said member extending from said intersected roll end.

6. A syphon system particularly suitable for use with small bore heat exchanging rotary rolls having an axial bore intersecting an end of the roll comprising, in combination, a heat exchanging medium receiving member having an axis and a generally cylindrical periphery of a diameter slightly smaller than the roll bore, an opening defined in said member adjacent the periphery thereof, a first conduit affixed to said member communicating with said opening and axially extending away from said member for extending through the roll intersected end, and sealing means mounted on said member extending about the periphery thereof and located in the axial direction of said member intermediate said opening and said first conduit.

7. A syphon system as in claim 6 wherein said member includes a large diameter portion and a smaller diameter portion, said opening intersecting said smaller diameter portion, said sealing means being disposed about said large diameter portion.

8. A syphon system as in claim 6 wherein a heat exchanging medium inlet passage is defined in said member, a supply conduit afiixed to said member substantially concentric thereto and communicating with said inlet passage, said first conduit being located within said supply conduit.

References Cited UNITED STATES PATENTS 1,754,826 4/ 1930 Hitchcock 16589 1,939,967 12/1933 Fox l89 2,870,546 1/1959 Nelson 89 3,217,794 11/1969 Meyer 16589 MEYER PERLIN, Primary Examiner US. Cl. XR. 

